Optimization of calcium carbonate content on synthesis of aluminum foam and its compressive strength characteristic

One of the most important characteristic of aluminum foam is compressive strength, which is reflected by its impact energy and Young’s modulus. In the present research, optimization of calcium carbonate (CaCO₃) content in the synthesized aluminum foam in order to obtain the highest compressive strength was carried out. The results of this study will be used to determine the CaCO₃ content synthesis process parameter in pilot plant scale production of an aluminum foam. The experiment was performed by varying the concentration of calcium carbonate content, which was used as foaming agent, at constant alumina concentration (1.5 wt%), which was added as stabilizer, and temperature (725°C). It was found that 4 wt% CaCO₃ gave the lowest relative density, which was 0.15, and the highest porosity, which was 85.29%, and compressive strength of as high as 0.26 Mpa. The pore morphology of the obtained aluminum foam at such condition was as follow: the average pore diameter was 4.42 mm, the wall thickness minimum of the pore was 83.24 µm, roundness of the pore was 0.91. Based on the fractal porosity, the compressive strength was inversely proportional to the porosity and huddled on a power law value of 2.91.